USPTO Patents Application 10561482

WO 2005/014680

1

PCT/EP2004/007897

10

20

Inier.t-.inn M olding gglvmer

This invention relates to a new polymer for
injection moulding, in particular to a bimodal
terpolymer composition which gives rise to a polymer
having ideal properties for injection moulding
especially for moulding articles which will be used in
contact with food.

Linear low density polyethylenes (LLDPE's) are
widely used in the manufacture of packaging products
which are typically produced by injection moulding
Conventional LLDPE's are made using Ziegler-Natta
catalysis and therefore have broad molecular weight
15 distributions .

in many applications, e.g. where food products are
being packaged, it is essential that the injection
moulded article, e.g. container or closure means
therefor, does not contaminate the product. For these
applications, an indication of the degree of
contamination may be obtained from tests which
determine the level of migration of the polymer
material, e.g. when immersed in olive oil or hexane
Ziegler-Natta produced LLDPE polymers have been found
25 to exhibit high levels of migration, i.e. foods in
contact with Ziegler-Natta LLDPE's may become
contaminated with polymer, and are therefore unsuitable
for use in applications such as food and medical
product packaging, especially where contact with fatty
30 foods is made.

LLDPE's made using single site catalysis, in
particular those produced using metallocenes
(mLLDPE 1 s) , have been found to give rise to injection
moulded articles having acceptable levels of migration
35 due to their much narrower molecular weight

distributions and molecular weight independent short
cham branching distribution (SCBD) . As discussed in
WO01/96419 such LLDPE's are particularly useful for-

WO 2005/014680

PCT7EP2004/007897

packaging fatty foods. However, mLLDPE 1 s exhibit low
shear thinning and do not therefore exhibit ideal
processability .

When the mLLPDE is exposed to shear, e.g. during

5 the screw and melting procedure prior to injection into
the mould, its lack of shear thinning causes high
pressure build up in the injection moulding machine,
increased motor load, etc. Thus, the polymer is
generally hard to process. This problem has been

10 solved by the inclusion of long chain branches into the
mLLDPE and these can be introduced by, for example,
blending with high pressure polyethylene, post reactor
treatment or in situ formation.

However, blending and post reactor treatment of
15 the polymer are cost intensive procedures and the in
situ formation of long chain branches requires
particular single site catalysts and polymerisation
conditions. Thus long chain branching inclusion is not
favoured.

20 It is also known that mechanical properties, e.g

impact properties, can be generally improved by
employing higher olefins. Thus whilst 1-butene is a
commonly used comonomer, improved mechanical
properties, e.g. impact properties, can be obtained

25 relative to 1-butene using 1-hexene as comonomer.

The use of higher alpha-olefin comonomers, i.e. C 4
or greater alpha-olef ins, however increases the cost of
the polymer product and, generally, the efficiency of
comonomer incorporation decreases as the carbon content

30 of the comonomer increases, i.e. hexene is less

efficiently incorporated than butene and octene is less
efficiently incorporated than hexene, etc. For cost
and efficiency reasons therefore, incorporation of
higher alpha olefins is not always favoured.

35 There remains a need therefore to manufacture

polymers for injection moulding which have, low
migration properties, excellent mechanical properties

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15

as well as high shear thinning and hence acceptable
processing properties. The polymers must also be cheap
to manufacture to satisfy the packaging market.
We have now surprisingly found that by
5 incorporating two different alpha-olefin comonomers

into a polyethylene polymer, a multimodal polyethylene
terpolymer product may be produced which has ideal
properties for injection moulding compared to
polyethylenes produced using either of the comonomers
10 as the sole comonomer. The polyethylene terpolymers of
the invention possess a multimodal molecular weight
distribution therefore giving rise to improved
processability and mechanical properties whilst
migration is kept to a minimum by the different
densities of the . terpolymer component and the resulting
reduction in short chain branching in the shorter chain
components .

Thus, viewed from one aspect the invention
provides the use of a multimodal, e.g. bimodal,
polyethylene composition comprising as comonomers to
ethylene at least two C 4 . u alpha olefins, preferably at
least two alpha olefins selected from but-l-ene, hex-1-
ene, 4 -methyl -pent- 1-ene, hept-l-ene, oct- 1-ene, and
dec-l-ene, particularly but-l-ene and hex-l-ene in
25 injection moulding. *

Viewed from another aspect the invention provides
an injection moulded article produced from a multimodal
polyethylene composition comprising as comonomers to
ethylene at least two C 4 . 12 alpha olefins, preferably at
30 least two alpha olefins selected from but-l-ene, hex-l-
ene, 4 -methyl -pent -1-ene, hept-l-ene, oct-l-ene, and
dec-l-ene, particularly but-l-ene and hex-l-ene.

Typically, the polyethylene composition is a
mixture of two or more polyethylenes, e.g. produced by
35 blending or by two-or-more stage polymerization
reactions. The constituent polyethylenes may be
homopolymers , copolymers, terpolymers or polymers of

20

WO 2005/014680 PCT/EP2004/007897

4

four or more comonomers; preferably however at least
one polymer is a terpolymer or at least two polymers
are copolymers, in particular in which one monomer, the
major component, is ethylene and one or two comonomers,

5 the minor components, are C 4 and/or C 6 alpha-olef ins .
In an especially preferred embodiment, the
polyethylene composition comprises an ethylene/ 1 -but ene
copolymer fraction and an ethylene/l-butene/l-hexene
terpolymer fraction.

10 It is especially preferred that the polymer be

prepared in a two or more stage polymerization in which
in an earlier stage the lower alpha-olefin comonomer
(e.g. 1-butene) is incorporated and in which in a later
stage the higher alpha-olefin comonomer is incorporated

15 (e.g. 1-hexene) . Nonetheless, it is within the scope
of the invention to produce the polymer in a two stage
polymerization reaction in which an ethylene
homopolymer is produced in the first stage and an
ethylene terpolymer is produced in the second stage or

20 vice versa or in which an ethylene copolymer with the
higher alpha-olefin comonomer is produced in the first
stage and an ethylene copolymer with the lower alpha-
olefin comonomer is produced in the second stage.
Likewise, an ethylene copolymer may be produced in the

25 first stage and an ethylene terpolymer in the second

stage and vice versa. Terpolymers may also be produced
in both stages although preferably a lower molecular
weight higher, density terpolymer is formed in a first
stage with a higher molecular weight lower density

30 terpolymer being formed in a second stage.

The expression "homopolymer" of ethylene used
herein refers to a polyethylene that consists
substantially, i.e. at least 98% by weight, preferably
at least 99% by weight, more preferably at least 99.5%

35 by weight, most preferably at least 99.8% by weight, of
ethylene .

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The ethylene polymers of the injection moulded
articles of the invention can be produced using a
Ziegler-Natta catalyst or a single site catalyst.

Preferably however, the polyethylene polymers of

5 use in the invention are produced using a so-called
single site catalyst, e.g. a catalyst comprising a
metal coordinated by one or more r|-bonding ligands.
Such ri-bonded metals are normally referred to as
metallocenes and the metals are typically Zr, Hf or Ti,

0 especially Zr or Hf . The ^-bonding ligand is typically
an r| s -cyclic ligand, i.e. a homo or heterocyclic
cyclopentadienyl group optionally with fused or pendant
substituents. Such metallocene catalysts have been
widely described in the scientific and patent

5 literature for about twenty years. Such metallocene
catalysts are frequently used with catalyst activators
or co-catalysts, e.g. alumoxanes such as
methylaluminoxane, again as widely described in the
literature .

0 Preferred metallocenes are optionally bridged

bisindenyl or biscyclopentadienyl compounds with Hf , Zr
or Ti. The -q-ligands can carry typical substituents,
preferably up to 5, e.g. 1 or 2, C^-alkyl substituents
as is known in the art. The metal ions conventionally

5 are coordinated to sigma ligands, e.g. two chloride
ligands. Bridges are typically ethylene or silyl
based, e.g. dimethyl s ilyl .

The polymer used in the articles of the invention
is multimodal, preferably bimodal, i.e. its molecular

0 weight profile does not comprise a single peak but

instead comprises the combination of two or more peaks
(which may or may not be distinguishable) centred about
different average molecular weights as a result of the
fact that the polymer comprises two or more separately

5 produced components. In this embodiment, a higher

molecular weight component preferably corresponds to a

WO 2005/014680 PCT7EP2004/007897

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copolymer (or terpolymer etc.) of the higher alpha-
olefin comonomer and a lower molecular weight component
preferably corresponds to an ethylene homopolymer or a
copolymer (or terpolymer etc.) of the lower alpha-

5 olefin comonomer. Such bimodal ethylene polymers may
be prepared for example by two or more stage
polymerization or by the use of two or more different
polymerization catalysts in a one stage polymerization.
Preferably however they are produced in a two- stage

10 polymerization using the same catalyst, e.g. a
metallocene catalyst, in particular a slurry
polymerization in a loop reactor followed by a gas
phase polymerization in a gas phase reactor. A loop
reactor - gas phase reactor system is marketed by

15 Borealis A/S, Denmark as a BORSTAR reactor system.

Preferably, the lower molecular weight polymer
fraction is produced in a continuously operating loop
reactor where ethylene is polymerized in the presence
of a polymerization catalyst as stated above and a

20 chain transfer agent such as hydrogen. The diluent is
typically an inert aliphatic hydrocarbon, preferably "
isobutane or propane. A C 4 to C 12 -olefin comonomer is
preferably added to control the density of the lower
molecular weight copolymer fraction.

25 Preferably, the hydrogen concentration is selected

so that the lower molecular weight copolymer fraction
has the desired melt flow rate.

In the case where the target density of the lower
molecular weight copolymer fraction exceeds 955 kg/m 3 ,

30 it is advantageous to operate the loop reactor using
propane diluent in so called supercritical conditions
where the operating temperature exceeds the critical
temperature of the reaction mixture and the operating
pressure exceeds the critical pressure of the reaction

35 mixture. A preferred range of temperature is then from
90 to 110°C and the range of pressures is from 50 to 80
bar.

WO 2005/014680 PCT/EP2004/007897

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The slurry is intermittently or continuously
removed from the loop reactor and transferred to a
separation unit where at least the chain transfer
agents (e.g. hydrogen) are separated from the polymer.

5 The polymer containing the active catalyst is then
introduced into a gas phase reactor where the
polymerization proceeds in the presence of additional
ethylene, comonomer(s) and optionally chain transfer
agent to produce the higher molecular weight copolymer

10 fraction. The polymer is intermittently or continuously
withdrawn from the gas phase reactor and the remaining
hydrocarbons are separated from the polymer.

The conditions in the gas phase reactor are
selected so that the ethylene polymer has the desired

15 properties. Preferably, the temperature in the reactor
is between 70 and 100°C and the pressure is between 10
to 40 bar. The hydrogen to ethylene molar ratio ranges
from preferably 0 to 1 mol/kmol, more preferably 0 to
0.5 mol/kmol and the alpha-olefin comonomer to ethylene

20 molar ratio ranges from preferably 1 to 100 mol/kmol,
more preferably 5 to 50 mol/kmol and most preferably" 5
to 30 mol/kmol.

The injected moulded article of the invention may
be prepared using conventional injection moulding

25 apparatus, e.g. a repetitive process in which plastic
is melted and injected into a mould cavity where the
article is cooled down. After cooling, the mould opens
and the article is ejected.

The melt can be prepared conventionally in a screw

30 set up which acts to melt and homogenise the polymer
while slowly retracting to build up the melt reservoir
necessary for the injection step. The screw can then
be used as a plunger in a forward movement to inject
the melt through the runner, optionally a manifold and

35 the gate into the mould.

Whilst the polyethylene composition may be used to
make any injection moulded article it is preferred if

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the articles are for use in medical or food packaging
in particular closure means such as lids or plastic
storage containers or eating/drinking containers e.g.
cups, bowls, dishes etc.

5 Viewed from a further aspect the invention

provides a product (e.g. foodstuff, medical product
etc) packaged within an injection moulded article as
hereinbefore described. The articles of the invention
are particularly suited to packaging fatty foods.

10 The article of the invention is preferably formed

from either (I) a bimodal polyethylene composition
comprising

a) a lower molecular weight homopolymer of
15 ethylene and

b) a higher molecular weight terpolymer of
ethylene, 1-butene and a C 5 to C 12 alpha -
olefin (e.g. C 6 to C 12 alpha-olef in) ; or

20

(II) a bimodal polyethylene composition comprising

a) a lower molecular weight polymer which is a
binary copolymer of ethylene and 1-butene or
25 1-hexene and

b) a higher molecular weight polymer different

from a) which is either a binary copolymer of
ethylene and 1-hexene, or a terpolymer of
30 ethylene, 1-butene and a C 5 to C 12 alpha-

olef in (e.g. C 6 to C 12 alpha-olef in) ; or

(III) a bimodal polyethylene composition comprising

35 a) a lower molecular weight polymer which is a

terpolymer of ethylene, 1-butene and 1-
hexene , and

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PCT/EP2004/007897

b) a higher molecular weight polymer which is a
terpolymer of ethylene, 1-butene and 1-
hexene .

5

The polymers used in the manufacture of these
articles may themselves be new and hence form a still
yet further aspect of the invention*

In a preferred embodiment the present invention
10 provides an article of a bimodal polymer with a

relatively narrow molecular weight distribution (MWD) ,
good processability, and a low level of extractibles .
The MWD is preferably 2 to 25, e.g 2 to 10, more
preferably 2.0 to 8.0, e.g. 2.0 to 6.0 or 3.0 to 8.0,
15 especially 2.5 to 4.5.

The weight average molecular weight of the
multimodal e.g. bimodal polymer is preferably between
15,000 and 250,000 g/mol, e.g. 20,000 to 180,000,
preferably 30,000 to 140,000.
20 The molecular weight distribution of the polymer

is further characterized by the way of its melt flow"
rate (MPR) according to ISO 1133 at 190°C. The final
multimodal e.g. bimodal polymer preferably has a melt
flow rate MFR 2 of 0.4 to 100 g/lOmin, more preferably of
25 0.8 to 80 g/lOmin, especially 1.5-40 g/lOmin. The lower
molecular weight polymer fraction preferably has a melt
index MFR 2 of 1 to 400 g/lOmin, more preferably of 10 to
200 g/lOmin, especially 50 to 150 g/lOmin.

The melt flow rate and the density of the material
30 are decisive for strength properties .

The density of the final multimodal e.g. bimodal
polymer is preferably 870 to 940 kg/m 3 , more preferably
of 890 to 935 kg/m 3 , especially 905 to 930 kg/m 3 . The
density of the lower molecular weight polymer fraction
35 is preferably 905 to 975 kg/m 3 , more preferably 915 to
950 kg/m 3 , especially 920 to 945 kg/m 3 , e.g. 930 kg/m 3 or
greater. The density of the lower molecular weight

WO 2005/014680 PCT/EP2004/007897

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fraction of the polyethylene composition should
preferably be greater than that of the higher molecular
weight composition .

The multimodal e.g. bimodal polymer according to
5 the present invention preferably comprises 10 to 70%,
more preferably 20 to 65% and most preferably 40 to 60%
by weight of the lower molecular weight copolymer
fraction with regard to the total composition.

The overall comonomer content in the polymer is
10 preferably 0.1 to 10 mol%, preferably 0.5 to 7 mol% and
in the lower molecular weight polymer the comonomer
content is preferably 0 to 3.0 mol%, preferably 0 to
2.5 mol%. In the higher molecular weight polymer the
comonomer content is preferably 0.1 to 10 mol%,
15 preferably 0 . 1 to 7 mol% . Comonomer contents may be
measured by NMR.

Further, the molecular weight of the higher
molecular weight copolymer fraction should be such that
when the lower molecular weight copolymer fraction has
20 the melt index and density specified above, the final
multimodal polymer has the melt index and density as"
discussed above.

The final multimodal e.g. bimodal polymer
preferably has a tensile modulus '(IS0527-2) of 10 to
25 500 MPa, preferably 30 to 450 MPa, especially 60 to 400
MPa.

The final multimodal e.g. bimodal polymer
preferably has an Impact strength (IS0179 23°C) of at
least 30 kJ/m 2 , preferably at least 40 kJ/m 2 , especially

30 at least 50 kJ/m 2 .

The final multimodal e.g. bimodal polymer
preferably has a hexane extractable fraction of less
than 5, preferably less than 3, more preferably less
than 2.5, especially less than 2 wt% .

35 The final multimodal polymer preferably has a low

level of migration measured by immersion in olive oil

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(as in Example 6) of less than 10, preferably less than
5, especially less than 3 mg/dm 2 .

It has surprisingly been found that for the same
density the polymers of the invention exhibit high

5 tensile modulus and high impact strength compared to
conventional copolymers. In general, stiffness
(tensile strength) and impact are intrinsically linked
to crystallinity and thereby the density. So
increasing density increases stiffness and decreases

10 impact. However, in the polymers of the invention high
stiffness and high impact strength are observed even at
relatively high densities. This stiffness/impact
balance allows the production of injected moulded
articles with reduced wall thicknesses, i.e. lighter

15 and cheaper injected moulded articles and also allows
cycle times to be decreased, i.e. increase the number
of injections per minute. Hence the polymers of the
invention allow the production of more articles at less
cost than is conventionally achieved.

20 In addition to the polymer itself, the composition

and injection moulded article of the invention may also
contain antioxidants, process stabilizers, pigments and
other additives known in the art.

The present invention will now be illustrated

25 further by the following non-limiting Examples:

Experimental :
MFR

30 MFR was measured according to ISO 1133 at 190°C. The
load has been indicated as a subscript, i.e. MFR 2
denotes the measurement has been carried out under a
load of 2.16 kg and MFR 2X denotes the measurement has
been carried out under a load of 21.6 kg, respectively.

35

M^, and MWD :

The weight -average molecular weight M^,, and the

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molecular weight distribution (MWD = M^/V^, where M n
equals number- average molecular weight) is measured by
a method based on ISO/TC61/SC5 N 5024. The difference
between this method and the method used is the
5 temperature; the ISO method being at room temperature
while the method used being at 140°C. The ratio of IV^
and M n is a measure of the broadness of the
distribution, since each is influenced by the opposite
end of the "population" .

10

Density:

Density is measured according to ISO 1183 /D.

1-butene and 1-hexene contents:

15 l-butene and 1-hexene contents of the polymers were
determined by 13 C NMR.

Extractables in hexane :

Hexane extractions are carried out using ASTM D5227.
Rheology :

The rheological properties of the polymers were
determined using Rheometrics RDA II Dynamic Rheometer.
The measurements were carried out at 190°C under a
nitrogen atmosphere. The measurement give storage
modulus (G 1 ) and loss modulus (G") together with
absolute value of complex viscosity (*) as a function
of frequency or absolute value of complex modulus (G*) ,
where :

* = ((G' 2 + G" 2 )/ ) H
G* - (G |2 + G" 2 )*

In the present method, viscosity at low shear rates
(0.05 rad/s) is plotted against viscosity at high shear
rates (300 rad/s) as a measure of processability; a
high viscosity at low shear rates combined with a low

25

4 30

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viscosity at high shear rates giving superior
processability .

Catalyst Preparation

5 Example 1:

134 grams of a metallocene complex (bis (n-
butylcyclopentadienyl) hafnium dichloride supplied by
Witco as TA02823, containing 0.36 % by weight Hf) and
9.67 kg of a 30% solution of methylalumoxane (MAO) in

10 toluene (supplied by Albemarle) were combined and 3.18
kg dry, purified toluene was added. The thus obtained
complex solution was added on 17 kg silica carrier
Sylopol 55 SJ by Grace. The complex was fed very slowly
with uniform spraying during 2 hours. Temperature was

15 kept below 30°C. The mixture was allowed to react for 3
hours after complex addition at 30 °C. The thus obtained
solid catalyst was dried by purging it with nitrogen at
50 °C for three hours and recovered.

20 Polymeristion
Example 2 :

A continuously operating loop reactor having a volume
of 500 dm 3 was operated at 85 °C temperature and 60 bar
pressure. Into the reactor were introduced propane

25 diluent, ethylene, 1-butene comonomer, hydrogen and the
polymerisation catalyst prepared according to Catalyst
Preparation Example 1 in such amounts that the ethylene
concentration in the liquid phase of the loop reactor
was 7.2 % by mole, the ratio of hydrogen to ethylene

30 was 0.63 mol/kmol, the ratio of 1-butene to ethylene

was 155 mol/kmol and the polymer production rate in the
reactor was 30 kg/h. The thus formed polymer had a
melt index MFR 2 of 120 g/10 min and a density of 936
kg/m 3 .

35 The slurry was intermittently withdrawn from the

reactor by using a settling leg and directed to a flash
tank operated at a temperature of about 50 °C and a_.

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pressure of about 3 bar.

From the flash tank the powder, containing a small
amount of residual hydrocarbons, was transferred into a
gas phase reactor operated at 75 °C temperature and 20
5 bar pressure. Into the gas phase reactor were also

introduced additional ethylene, 1-hexene comonomer and
nitrogen as inert gas in such amounts that the ethylene
concentration in the circulating gas was 19% by mol,
the ratio of hydrogen to ethylene . was about 1 . 0
10 mol/kmol, the ratio of 1-hexene to ethylene was 12

mol/kmol and the polymer production rate was 30 kg/h.
The concentration of 1-butene was so low that it could
not be detected by the on-line gas chromatograph which
was used to monitor the gas composition.
15 The polymer collected from the gas phase reactor

was stabilised by adding to the powder 400 ppm Irganox
B561. The stabilised polymer was then extruded and
pellet ised under nitrogen atmosphere with a CIM90P
extruder, manufactured by Japan Steel Works. The melt
20 temperature was 200 °C, throughput 2 80 kg/h and the
specific energy input (SEI) was 200 kWh/t.

The production split between the loop and gas phase
reactors was thus 50/50. The polymer pellets had a melt
index MFR 2 of 20 g/10 min, a weight average molecular
25 weight M*, of 59600 g/mol, a number average molecular
weight of 16900 g/mol and a z-average molecular
weight M z of 134000 g/mol. Further, the polymer had a
zero shear rate viscosity T] 0 of 460Pa-s, and a shear
thinning index SHI 0/100 of 2.7.

30

Example 3 (Comparative) :

A continuously operating loop reactor having a volume
of 50 0 dm 3 was operated at 85 °C temperature and 60 bar
pressure. Into the reactor were introduced propane
35 diluent, ethylene, 1-butene comonomer, hydrogen and the
polymerisation catalyst prepared according to Catalyst
Preparation Example 1 in such amounts that the ethylene

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concentration in the liquid phase of the loop reactor
was 6.6 % by mole, the ratio of hydrogen to ethylene
was 0.63 mol/kmol, the ratio of 1-butene to ethylene
was 183 mol/kmol and the polymer production rate in the
5 reactor was 25 kg/h. The thus formed polymer had a melt
index MFR 2 of 120 g/10 min and a density of 93 6 kg/m\

The slurry was intermittently withdrawn from the
reactor by using a settling leg and directed to a flash
tank operated at a temperature of about 50 °C and a

10 pressure of about 3 bar.

From the flash tank the powder, containing a small
amount of residual hydrocarbons, was transferred into a
gas phase reactor operated at 75 °C temperature and 20
bar pressure. Into the gas phase reactor were also

15 introduced additional ethylene, 1-butene comonomer and
nitrogen as inert gas in such amounts that the ethylene
concentration in the circulating gas was 23% by mole,
the ratio of hydrogen to ethylene was about 1.2
mol/kmol, the ratio of 1-butene to ethylene was 48

20 mol/kmol and the polymer production rate was 26 kg/h.
The production split was thus 49/51. No 1-hexene was -
introduced into the gas phase reactor.

The polymer collected from the gas phase reactor
was stabilised by adding to the powder 400 ppm Irganox

25 B561. The stabilised polymer was then extruded and
pelletised under nitrogen atmosphere with a CIM90P
extruder, manufactured by Japan Steel Works. The melt
temperature was 200 °C, throughput 280 kg/h and the
specific energy input (SEI) was 200 kWh/t.

30 The production split between the loop and gas phase

reactors was thus 49/51. The polymer pellets had a melt
index MFR^ of 10 g/10 min, a density of 916 kg/m\ a 1-
butene content of 8.1 % by weight, a weight average
molecular weight M„ of 67800 g/mol, a number average

35 molecular weight M,, of 19 600 g/mol and a z-average
molecular weight M z of 140000 g/mol. Further, the
polymer had a zero shear rate viscosity ti 0 of 800 Pa-s,

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and a shear thinning index SHI 0/100 of 2.4.
Polymerisation reactor conditions

HiXalupic

-3

C 2 HI XOvJJJ, UKJJL — o

*

*7

/ . a

o . o

iri 2 / XII JL (JvJJJ i lUO JL / JvUlvJX

u . o z>

^4/ v- 2 XII JLvJUp, UlvJX / iV,ULUX

JLD3

Xoj

L- 6 / v—2 in loop, luoi / js_luo J.

U

u

i v Jr k 2 or loop poiymer, y / iu mm

ion

ion
1Z u

jjensicy or loop polymer/ Jtg/m

Production rate in loop, kg/h

30

25

C 2 = in gpr, mol-%

19

23

H 2 /C 2 in gpr, mol/kmol

1.0

1,2

C 4 /C 2 in gpr, mol/kmol

*

48

C 6 /C 2 in gpr, mol/kmol

12

0

Production rate in gpr, kg/h

30

26

Production split, Loop/gpr

50/50

49/51

* indicates that the level was
oy GC

too low to be dete<

Polymer properties

Example

2

3

MFR 2 , g/10 min

20

10

Density, kg/m 3

915

915

M z /1000

134

140

iy^/iooo

59.6

67.8

M n /1000

16.9

19.6

r| 0 , Pa-s

460

800

SHI 0/100

2.7

2.4

Tlx, 2a-s

440

780

SHI 1/100

2.6

2.3

G 1 5kPa t P a

810

630

117.3

115 .8

Crystallinity , %

36.7

36.7

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Example 4: Tensile Modulus and Impact properties

The tensile modulus and charpy impact were measured on
injection moulded specimens. The results are given in
table 3 .

5

Table 3

Property

Standard

Unit

Example 2

Example 3

Comonomer

1-butene+l-
hexene .

1-butene

Tensile
Modulus

ISO 527-2

MPa

190

165

Charpy
Impact; 23 °C

ISO 179

kJ/m 2

58

55

Density

ISO 1183-D

kg/m 1

915, 5

915, 8

Example 5

Comparative sample 1:

The polymer was manufactured and sold by Borealis under
trade name LE8030. This an ethylene butene copolymer
formed by Z/N catalysis and has an MFR 2 of 28 g/10 min
and density of 919 kg/m 3 .

Comparative sample 2 :

The polymer manufactured and sold by Borealis under
trade name MA8200. MA8200 is a LDPE for injection
moulding. The polymer has an MFR 2 of 7.5 g/10 min,
tensile modulus of 140 MPa and density of 920 kg/m 3 .

Migration and extraction data for compression moulded
samples

2 mm thick compression moulded sheets of the polymer
from example 2 and the comparative samples were
prepared according to IS01872-2 and subjected to
migration tests by total immersion in olive oil at 40 °C

WO 2005/014680

PCT/EP2004/007897

18

for 10 days. Hexane extractions were carried out using
ASTM D5227. The results are shown in Table 4.

Table 4

Polymer ' "

Ex 2

LE8030

MA8200

Extract xbles in hexane (%wt)

1,1

5,3

1,4

Migration (mg/dm 2 )

0

48, 8"

14